Reciprocating mechanism.



BALS-TON'.

RBCIPROGATING MBGHANISM.

APPLICATION FILED ANLZO, 1907.

Patented Feb. 7, 1911.

s 'sHEIJTs-sHEET 1.

H. H. RALSTON.

BBGIPROGATING MBGHANISM. v

APPLICATION FILED APB..20,1907, 983,399 Patented 1191111911.

3 SHEETS-SHEET 2.

H. H1 RALSTON.

RECIPROGATING MEGHANISM.

APPLIOATION FILED .APB.20, 1907.

983,399. e Patented Fee?, 1911.

3 SHEETS-*SHEET 3.

Cil

UNITED OFFICE.

HOWARD H. RALSTON, OF NORWGOD, OHIO, ASSIGNOR TO. ALLIS-CHALMERSCOMPANY, A CORPORATION OF NEW JERSEY, AND THE BULLOCK ELECTRIClVIANUFACTURINGr .COMPANY, A CORPORATION OF OHIO.

RECIPROCATING MECHANISIVI.

To all ywhom it may concern:

Be it known that I, Howiiuo H. RALs'roN, a citizen of the United States,residing` at Norwood, in the county oli Hamilton and. State ot Ohio,have invented certain new and use't'ul. Improvements in ReciprocatingMechanism, ot which the following is a full, clear, and exactspecification.

My invention relates to dynamo-electric machines and particularly tomeans for imparting an axial reciprocatory movement to the brushes.

It the brushes of a machine are lixed and bear for a considerable timeon the same portions of the eommutator or collector rings there a`liability that the commutator or collector rings will become O'rooved orroughened, thus shortening` the liite ot the latter and resulting insparking and an increase in trictional loss. To overcome this ditlicultyit has been proposed to slowly reciprocate the brushes in the directionot the longitudinal axis of the machines by reciprocating the brush yokeand auxiliary brush supl'iorting members carried thereby. The meansgenerally employed for reciprocating` the brush yokes are thosedisclosed in the U. patents to Johnson, 788,049, April 535, 1905, andRambeau, 826,526, July 1T, 1906. As shown in these patents the yokes areslowly reciprocated by imparting1 thereto step by step reciprocatorymovements by means of cams and ratchet mechanisms operated from theshalts of the machine.

The object ol my invention is to improve the devices disclosed in thepatents above referred to and to provide a novel form ol brushreciproca-ting means which will be et# i'eetive in operation, simple inconstruction, and inexpensive to manufacture.

In carrying out my invention, I provide means t'or imparting to thebrushes an axial reciproeatory movement without reciprocating the yoke.The reciprocatory move ments are preferably imparted to the dilterentbrushes or groups of brushes independently, so that it desired, partonly of the brushes may be reciiirocated, the positions of the othersbeing fixed, it being unnecessary to reciprocate all the brushes toprevent grooving and roughening of the commutator. The brushes which arenot reciprocated are supported in the usual brush forks or othersupporting member connect- Specficaton of Letters Patent.

Application filed April 20, 1907.

Patented Feb. 7, 1911.

Serial No. 369,220.

ed to the yoke, and the brushes which are reeiprocated are so mounted asto be mov able relatively to the supporting` members, which may be ofspecial construction. Means are provided on each of said last namedbrush forks for reciprocating the brushes. A variety of lorms ofreciprocating means may be employed, the one here shown comprisingratchet and cam mechas nisms driven or actuated by the rotation of themachine. Also the reciprocating` brush holders may be supported andmounted in a variety of ways.

My invention further consists in certain novel means l'or supporting ormounting, connecting, and reciprocating the brushes and holders, all ofwhich will be more fully described in thev following detaileddescription.

In the drawings, which show several forms or embodiments of myinvention, F igure l is a partial end elevation of a inachine equippedwith my invention; Fig. 2 is an enlarged end view showing thereciprocating mechanism; F 3 is a partial side sectional elevationshowing a brush fork and attached brush reciprocating mechanism; Fig. 4ris a sectional View along the line Ll-Llol Fig. 3; Fig. 5 is a detail ofa portion ot the brush reciprocating mechanism; Fig. 6 is a` viewsimilar to Fig. 3 showing` a modiication; Fig. T is a sect-ion along theline 7-7 of Fig. 6; Fig. 8 is a view similar to Figs. and G showing a'further modilication; and Fig. 9 is a section along the line 9 9 otFig. S.

Referring tirst to Figs. 1, Q, 3, l and 5 ot the drawings, 10 indicatesthe field yoke, ll the armature, and l2 the commutator 01" a directcurrent dynamo-elcctrie machine equipped. with my invention. Supportedon rollers 13 on the side oi the lield iframe is ay brush yoke 1st otthe usual construction. Mounted on the brush yoke are ordinary brushforks l5 having brushes and holders 1G which are fixed in position andforks 15 which carry brushes and holders 1Ga adapted to be reciprocated.The ratio of fixed and reciprocatingl brushes can be made anythingdesired and can l e varied by substituting` one form of fork for theother. In Fig. l the brushes and holders supported hy every third brushitork are adapted to be reciprocated. The brushes and holders 1G are somounted as to be axially movable relatively to the forks 15a, the latterbeing provided with reciprocating devices or mechanisms which arepreferably actuated independently and successively by the rotary member.ln the embodiment of my invention here shown the reciprocatory brushholders are secured to studs 17 which have a sliding tit in the ends ofthe brush forks 15a and are adapted to be reciprocated therein. r1`heinner ends of the studs and openings in the inner arms of the forks arepreferably cylindrical for convenience in construction. The outer endsof the studs and openings in the outer brush forks may be so shaped asto prevent the studs from turning in the brush forks, or the studs orforks may be provided with keys or splines 18 for this purpose. As hereshown the outer arms of the forks are split and the pressure of thebearings on the stud can be adjusted by screws 19. In this instance eachstud 17 is adapted to be reciprocated by a separate ratchet mechanismand cam mounted on the brush fork. Mounted on a pin or stud on the outerarm of each brush fork 15a is a rotary member forming part of saidmechanism having a disk Q0 toothed or notched on its periphery and a hubQ1 having a cam slot 21a engaged'by a pin, screw or other projection Q2on the outer end of the stud 17. The disk and cam are adapted to berotated b v a pawl comprising` a verticalljvv movable rod supported on apair of arms 2st and 21H extendingl outwardly from the brush fork, saidrod having a finger 25 with a pivoted or hinged nose 25 adapted toengage the teeth of the disk. and on its lower end a roller or wheel 2G.The rod is adapted to move freely in the arms 24; and 24a, the downwardmovement being` limited by a block QT adjustably secured to the upperend of the rod above the arm Qt and adapted to engage the upper face ofsaid arm. A pin Q8 secured to the arm passes through the block QT andserves as a guide for the pawl. A spring 29 on the rod between the armQ4 and the finger holds the rod normally in its innermost position. Theend of the spring bears on the nose 25 to hold the latter in position toengage the teeth of the disk Q0 when the rod is moved outward. Theratchet. mechanism on each fork 15a is adapted to be operated in thisinstance by one or more shoes 30 (one beingl here shown) adjustablysecured to the end of the commutator by screws 31, in such a position asto engage the roller QG and lift the rod Q3 when the armature andcomn'iutator are rotated. The outer face of the shoe is curved as shownand is preferably covered by some comparatively soft material such asleather to reduce to a minimum the shock and noise of contact with therollers. To provide paths of low resistance between the brushes andholders which are reciprocatcd and the corresponding brush forks, Iconnect all the holders mounted on each stud 1T to the fork 15L by a lowresistance flexible conductor 32. As is shown, the conductor 32 issecured to the top of each brush holder by a screw 33 and is secured atone end to the fork by being clamped by one or more screws 34- in a slotin the arm of the fork. The brushes are electrically connected to thcholders and to the conductor 32 by tlexiw ble shunts or pig-tails 36 theend of the shunts being preferably clamped to the coni ductor 32 by thescrews The use of this conductor 39. connecting the ln'ush-holders andfork is not confined to holders which are reciprocated relatively to afork. but may be used with advantage when the brushes are fixed, as thebearing surfaces between the holders and studs, and studsl and forks aresometimes small. lVhen the machine is in operation. the shoe 30 mountedon the face of the armature engages successively the rollers QG of thereciprocating mechanisms on the brush forks 1511. Each roller is in turnlifted a distance depending upon the adjusted positions of the shoe androller. rotating the notched disk Q0 and the cam slotted hub 21, andthus slowly reciprocating step-by-step the studs 17 on which the brushesand holders 1Gn are mounted. The period of reciprocation can be variedby adjusting either the position of the shoe 30 or the positions of thevertically movable rod Q3 and rollers 2G, or by varying the number ofshoes BO employed. lf desired. different rates of reciprocation can atthe same time be imparted to the different groups of brushes by soadjusting the normal positions of the rods and rollers that themovements of the rods and arcsl through which the notched disks aremoved at each rotation are different.

rts stated before. the particular .supports or mountings for thereciprocatory brushes and holders may be widely varied. ln theniodiiication shown in Figs. (S and 'l' the brush stud is fixed in thebrush forks 15] and the brushes and brush holders are mounted on asleeve 23T which has a sliding i'it on the brush stud and is adapted tobe reciprocated by mechanism similar to that previously described. V[nthis case the notched or toothed disk and member 38 having a cam slot-3Sil are mounted on a pin or spindle passing through the outer arm ofthe brush fork, the member 3S being located on the inside of the arm.The sleeve 37 is provided with a pin, screw or other projection 39 whichengages the 'cam slot 38: The reciprocatingmechanism is otherwisc thesame as that first described. Then the machine is in operation theratchet and cam are actuated, slowly reciprocating the sleeve 3T and thebrushes and holders carried thereby. The brush holders are conl OOnected to the brush fork as in the firstinstance by a flexible conductor40.

In 8 and 9 I have shown a still further moditication. In this case thebrush holders have a sliding' lit, on the brush stud, which is `fixed inthe brush iork 15C as in the construction last described. As here shownthe brush holders are secured together by a rigid bar -l-l preferably ofconducting` material, one end of which bar is provided with a lug orprojection l2 which engages the cani slot l-lb oit' a rotary member 44:arranged and actuated as in the case last. described. The other end otbar Il extends upward and is connected to one end of a tlexibleconductor lo the other end of which is clamped or otherwise secured tothe brush fork. Thus when the armature and comnnitator are rotated theratchet and cam mechanism is actuated, slowly reciprocating,` the bar iland the brush holders attached thereto.

It will be seen that the details can be modified considerably withoutdepartingfrom the spirit and scope of my invention and I aim in myclaims to cover all such modifications.

IVhat I claim as new and desire to secure by Letters Patent is l. In adynamo-electric machine, a plurality ot lixed brushes, aI plurality ofmovable brushes, and means for imparting an axial reciprocatory movementto said movable brushes.

In a dynamo-electric machine, a brush yoke, a brush supporting' membersecured to said yoke, a group of brushes, and means carried by saidbrush supporting member for imparting an axial reciprocatory movement tothe brushes independently of the yoke.

In a dynamo-electric machine, a brush yoke, a` 'plurality of brushsupporting members secured thereto, brushes supported by said members,and means carried by one or more ot said members for imparting an axialreciprocatory movement. to the brushes supported thereby independentlyof the yoke.

4. In a dynamo-electric machine, a brush yoke, a plurality ot brushsupporting members secured thereto, a plurality of relatively fixedbrushes carried by some of said members, a plurality of brushes mountedfor movement in the direction of the axis of the machine and carried byother of said members, and means carried by said last named brushsupporting members for impart-ing` an axial reciprocatory movement tosaid movable brushes.

In a dynamo-electric machine, a brush yoke, a brush fork, a plurality ofbrushes and holders supported by said fork and mo'able relativelythereto in an axial direction, means carried by said fork it'orimparting an axial reciprocatory movement to said brushes independentlyor' the yoke, and means for operating said tirst named means by therotation ot the machine.

In dynamo-electric machine, a brush yoke, a brush simportingmembersecured thereto, a plurality of brushes and holders carried by saidmember, and means carried by said member for imparting to said brushesand holders an axial reciprocatory movement independently of the yoke,said means comprising` a rotary cam member.

7. In a dynamo-electric machine, a brush yoke, a brush fork, a brushstud carried by said fork, a brush and holder carried by said stud, andmeans dependent upon the operation of the machine for moving said brushand holder axially et' the machine and relatively to the brush i'ork.

8. In a dynamo-electric machine, a brush yoke, a brush fork, a brushstud carried by said lork, a plurality of brushes and holders mounted onsaid stud, and means dependent upon the operation ot the machine formoving said brushes and holders axially ot the machine and relatively tosaid fork.

9. In a. dyna1m electric machine, a brush yoke, a brush fork, a brushstud carried by said fork, a brush and holder mounted on said stud andmovable relatively to said fork, and means for reciprocating` said brushand holder.

10. In a dynamo-electric machine, the combination of the commutator, aplurality of brushes cooperating therewith, and means for automaticallymoving less than all of the said brushes relatively both to thecommutator and to the remainder ot' said brushes.

l1. In a dynamoelectric machine, the combination ot' a conunutator, aplurality of brushes cooperating therewith, and means for automaticallymoving less than all of said brushes axially of the commutator andrelatively to the remainder of said brushes.

In testimony whereof I atlix my signature, in the presence of twowitnesses.

I-IOIVARD II. RALSTON.

IVitnesses GEO. B. SoiiLnx, FRED J'. KINsnx.

